Assessment of the long-term population-level effects of HIV interventions is an ongoing public he... more Assessment of the long-term population-level effects of HIV interventions is an ongoing public health challenge. Following the implementation of a Transmission Reduction Intervention Project (TRIP) in Odessa, Ukraine, in 2013-2016, we obtained HIV pol gene sequences and used phylogenetics to identify HIV transmission clusters. We further applied the birth-death skyline model to the sequences from Odessa (n = 275) and Kyiv (n = 92) in order to estimate changes in the epidemic's effective reproductive number (R e) and rate of becoming uninfectious (δ). We identified 12 transmission clusters in Odessa; phylogenetic clustering was correlated with younger age and higher average viral load at the time of sampling. Estimated R e were similar in Odessa and Kyiv before the initiation of TRIP; R e started to decline in 2013 and is now below R e = 1 in Odessa (R e = 0.4, 95%HPD 0.06-0.75), but not in Kyiv (R e = 2.3, 95%HPD 0.2-5.4). Similarly, estimates of δ increased in Odessa after the initiation of TRIP. Given that both cities shared the same HIV prevention programs in 2013-2019, apart from TRIP, the observed changes in transmission parameters are likely attributable to the TRIP intervention. We propose that molecular epidemiology analysis can be used as a post-intervention effectiveness assessment tool.
Background
Estimation of temporal changes in HIV transmission patterns can help to elucidate the ... more Background Estimation of temporal changes in HIV transmission patterns can help to elucidate the impact of preventative strategies and public health policies.
Methods Portuguese HIV-1 subtype B and G pol genetic sequences were appended to global reference datasets to identify country-specific transmission clades. Bayesian birth-death models were used to estimate subtype-specific effective reproductive numbers (Re). Discrete trait analysis (DTA) was used to quantify mixing among transmission groups.
Results We identified five subtype B Portuguese clades (n=26-79 sequences) and a large monophyletic subtype G Portuguese clade (n=236). We estimated that major shifts in HIV-1 transmission occurred around 1999 (95% Bayesian credible interval 1998-2000) and 2000 (1998-2001) for subtypes B and G, respectively. For subtype B, Re dropped from 1.91 (1.73-2.09) to 0.62 (0.52-0.72). For subtype G, Re decreased from 1.49 (1.39-1.59) to 0.72 (0.63-0.8). The DTA suggests that people who inject drugs (PWID) and heterosexuals were at the source of most (>80%) virus lineage transitions for subtypes G and B, respectively.
Conclusions The estimated declines in Re coincide with the introduction of highly active antiretroviral therapy and the scale-up of harm reduction for PWID. Inferred transmission events across transmission groups emphasize the importance of prevention efforts for bridging populations.
Background: While HIV-1 subtype B has caused a large epidemic in the western world, its transmiss... more Background: While HIV-1 subtype B has caused a large epidemic in the western world, its transmission in Ukraine remains poorly understood. We assessed the genetic diversity of HIV-1 subtype B viruses circulating in Ukraine, characterized transmission group structure, and estimated key evolutionary and epidemiological parameters. Methods: We analysed 120 HIV-1 subtype B pol sequences (including 46 newly generated) sampled from patients residing in 11 regions of Ukraine between 2002-2017. Phylogenies were estimated using maximum likelihood and Bayesian phylogenetic methods. A Bayesian molecular clock coalescent analysis was used to estimate effective population size dynamics and to date the most recent common ancestors of identified clades. A phylodynamic birth-death model was used to estimate the effective reproductive number (Re) of these clades. Results: We identified two phylogenetically distinct predominantly Ukrainian (≥75%) clades of HIV-1 subtype B. We found no significant transmission group structure for either clade, suggesting frequent mixing among transmission groups. The estimated dates of origin of both subtype B clades were around early 1970s, similar to the introduction of HIV-1 subtype A into Ukraine. Re for Clade 1 was estimated to be 1.42 (95% HPD 1.26-1.56) and 1.69 (95% HPD 1.49-1.84) for Clade 2. Discussion: The subtype B epidemic in the country is no longer concentrated in specific geographical regions or transmission groups. The study results highlight the necessity for strengthening preventive and monitoring efforts to reduce the further spread of HIV-1 subtype B.
Introduction
Providing HIV healthcare and Treatment as Prevention both depend on diagnosing HIV c... more Introduction Providing HIV healthcare and Treatment as Prevention both depend on diagnosing HIV cases, preferably soon after initial infection. We hypothesized that tracing risk networks recruits higher proportions of undiagnosed positives than outreach-based testing or respondent-driven sampling (RDS) in Odessa, Ukraine.
Methods The Transmission Reduction Intervention Project (TRIP) used risk network tracing to recruit sexual and injection networks of recently-infected and longer-term infected (LTs) seeds (2013 to 2016). Integrated Biobehavioural Surveillance (IBBS) (2013) used RDS to recruit people who inject drugs (PWID). Outreach Testing tested PWID for HIV at community outreach sites (2013 to 2016). Proportions of undiagnosed positives among those tested were compared TRIP versus IBBS; TRIP versus Outreach Testing and between TRIP arms. Costs were compared across the projects.
Results TRIP tested 1252 people (21% women) in seeds’ risk networks; IBBS tested 400 (18% women); Outreach Testing 13,936 (31% women). TRIP networks included a higher proportion of undiagnosed positives (14.6%) than IBBS (5.0%) or Outreach Testing (2.4%); odds ratio (OR) 3.25 (95% CI 2.07, 5.12) versus IBBS and 7.03 (CI 5.95, 8.31) versus Outreach Testing respectively. Findings remained significant in analyses stratified by sex and when PWID in TRIP networks were compared with Outreach Testing and IBBS. Within TRIP, recently-infected participants’ networks contained higher proportions of undiagnosed positives (16.3%) than LTs’ networks (12.2%); OR 1.41 (CI 1.01, 1.95). TRIP located undiagnosed positives less expensively than did RDS or Outreach Testing.
Conclusions TRIP's recruiting techniques, including prioritizing networks of the recently infected, find undiagnosed HIV-positive people efficiently. They should be integrated with standard practice to improve case-finding. Research should test these techniques in other socio-epidemiologic contexts.
Ukraine has one of the largest HIV epidemics in Europe, historically driven by people who inject ... more Ukraine has one of the largest HIV epidemics in Europe, historically driven by people who inject drugs (PWID). The epidemic showed signs of stabilization in 2012, but the recent war in eastern Ukraine may be reigniting virus spread. We investigated the movement of HIV-infected people within Ukraine before and during the conflict. We analyzed HIV-1 subtype-A pol nucleotide sequences sampled during 2012–2015 from 427 patients of 24 regional AIDS centers and used phylogeographic analysis to reconstruct virus movement among different locations in Ukraine. We then tested for correlations between reported PWID behaviors and reconstructed patterns of virus spread. Our analyses suggest that Donetsk and Lugansk, two cities not controlled by the Ukrainian government in eastern Ukraine, were significant exporters of the virus to the rest of the country. Additional analyses showed that viral dissemination within the country changed after 2013. Spearman correlation analysis showed that incoming virus flow was correlated with the number of HIV-infected internally displaced people. Additionally, there was a correlation between more intensive virus movement and locations with a higher proportion of PWID practicing risky sexual behaviors. Our findings suggest that effective prevention responses should involve internally displaced people and people who frequently travel to war-affected regions. Scale-up of harm reduction services for PWID will be an important factor in preventing new local HIV outbreaks in Ukraine.
Early treatment, soon after infection, reduces HIV transmissions and benefits patients. The Trans... more Early treatment, soon after infection, reduces HIV transmissions and benefits patients. The Transmission Reduction Intervention Project (TRIP) evaluated a network intervention to detect individuals recently infected (in the past 6 months). TRIP was conducted in Greece (2013–2015) and focused on drug injector networks. Based on HIV status, testing history, and the results of an assay to detect recent infections, TRIP classified drug injector “Seeds” into groups: Recent Seeds (RS), and Control Seeds with Long-term HIV infection (LCS). The network members of RS and LCS were traced for two steps. The analysis included 23 RS, 171 network members of the RS, 19 LCS, and 65 network members of the LCS. The per-seed number of recents detected in the network of RS was 5 times the number in the network of LCS (Ratio RS vs. LCS: 5.23; 95% Confidence Interval (CI): 1.54–27.61). The proportion of recents among HIV positives in the network of RS (27%) was approximately 3 times (Ratio RS vs. LCS: 3.30; 95% CI: 1.04–10.43) that in the network of LCS (8%). Strategic network tracing that starts with recently infected persons could support public health efforts to find and treat people early in their HIV infection.
Objective: Although our understanding of viral transmission among people who inject drugs (PWID) ... more Objective: Although our understanding of viral transmission among people who inject drugs (PWID) has improved, we still know little about when and how many times each injector transmits HIV throughout the duration of infection. We describe HIV dynamics in PWID to evaluate which preventive strategies can be efficient. Design: Due to the notably scarce interventions, HIV-1 spread explosively in Russia and Ukraine in 1990s. By studying this epidemic between 1995 and 2005, we characterized naturally occurring transmission dynamics of HIV among PWID. Method: We combined publicly available HIV pol and env sequences with prevalence estimates from Russia and Ukraine under an evolutionary epidemiology framework to characterize HIV transmissibility between PWID. We then constructed compartmental models to simulate HIV spread among PWID. Results: In the absence of interventions, each injector transmits on average to 10 others. Half of the transmissions take place within 1 month after primary infection, suggesting that the epidemic will expand even after blocking all the post–first month transmissions. Primary prevention can realistically target the first month of infection, and we show that it is very efficient to control the spread of HIV-1 in PWID. Treating acutely infected on top of primary prevention is notably effective. Conclusion: As a large proportion of transmissions among PWID occur within 1 month after infection, reducing and delaying transmissions through scale-up of harm reduction programmes should always form the backbone of HIV control strategies in PWID. Growing PWID populations in the developing world, where primary prevention is scarce, constitutes a public health time bomb.
Background We studied the association between sex in exchange for money, drugs or goods and HIV f... more Background We studied the association between sex in exchange for money, drugs or goods and HIV for women who inject drugs (WWID) in Ukraine, as previous data on this association from the post-USSR region are contradictory.
Methods Data come from the Integrated Bio-Behavioral Survey of Ukrainian people who inject drugs collected in 2011 using respondent-driven sampling. Participants were interviewed and tested with rapid HIV tests.
Results The sample included 2465 WWID (24% HIV positive); 214 (8.7%) of which reported having had exchange sex during the last 90 days. Crude analysis showed no association between exchange sex and HIV (OR = 0.644; 95% CI 0.385–1.077). No confounders were found to alter this result in a multivariable analysis. Further modeling showed that exchange sex modifies association between HIV and alcohol use: no association between HIV and daily alcohol use was found for those women who exchanged sex (OR = 1.699, 95% CI 0.737–3.956); while not engaging in sex work and daily using alcohol reduced odds to be HIV infected (OR = 0.586, 95% CI 0.389–0.885).
Conclusions Exchange sex may have less impact on the HIV status of WWID who are exposed to injecting risks. The finding that daily alcohol use appears protective against HIV among WWID who do not exchange sex requires more research.
The number of public health applications for molecular epidemiology and social
network analysis h... more The number of public health applications for molecular epidemiology and social network analysis has increased rapidly since the improvement in computational capacities and the development of new sequencing techniques. Currently, molecular epidemiology methods are used in a variety of settings: from infectious disease surveillance systems to the description of disease transmission pathways. The latter are of great epidemiological importance as they let us describe how a virus spreads in a community, make predictions for the further epidemic developments, and plan preventive interventions. Social network methods are used to understand how infections spread through communities and what the risk factors for this are, as well as in improved contact tracing and message-dissemination interventions. Research is needed on how to combine molecular and social network data as both include essential, but not fully sufficient information on infection transmission pathways. The main differences between the two data sources are that, firstly, social network data include uninfected individuals unlike the molecular data sampled only from infected network members. Thus, social network data include more detailed picture of a network and can improve inferences made from molecular data. Secondly, network data refer to the current state and interactions within the social network, while molecular data refer to the time points when transmissions happened, which might have happened years before the sampling date. As of today, there have been attempts to combine and compare the data obtained from the two sources. Even though there is no consensus on whether and how social and genetic data complement each other, this research might significantly improve our understanding of how viruses spread through communities.
Current ideas about HIV prevention include a
mixture of primarily biomedical interventions, socio... more Current ideas about HIV prevention include a mixture of primarily biomedical interventions, socio-mechanical interventions such as sterile syringe and condom distribution, and behavioral interventions. This article presents a framework for socially-integrated transdisciplinary HIV prevention that may improve current prevention efforts. It first describes one socially-integrated transdisciplinary intervention project, the Transmission Reduction Intervention Project. We focus on how social aspects of the intervention integrate its component parts across disciplines and processes at different levels of analysis. We then present socially-integrated perspectives about how to improve combination antiretroviral treatment (cART) processes at the population level in order to solve the problems of the treatment cascade and make ‘‘treatment as prevention’’ more effective. Finally, we discuss some remaining problems and issues in such a social transdisciplinary intervention in the hope that other researchers and public health agents will develop additional socially-integrated interventions for HIV and other diseases.
Background The emergence of HIV-1 in Russia came soon after the collapse of the Soviet Union. Wit... more Background The emergence of HIV-1 in Russia came soon after the collapse of the Soviet Union. With more than half a million cases within 5 years, the post-soviet Russian epidemic is one of the fastest and largest HIV outbreaks ever recorded. Although driven by intravenous drug users (IDUs), why the epidemic spread so rapidly and on a large scale is unclear. One popular practice between 1990 and 2000 was to use blood as a buff er or as a purifi er of homemade narcotics; this practice could account for the massive spread of HIV among Russian IDUs. We aimed to assess whether the epidemic was driven by contamination of narcotics at their source rather than by needle sharing.
Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmiss... more Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users’ community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants.
Economic and political instability and related ''big events'' are widespread throughout the globe... more Economic and political instability and related ''big events'' are widespread throughout the globe. Although they sometimes lead to epidemic HIV outbreaks, sometimes they do not-and we do not understand why. Current behavioural theories do not adequately address these processes, and thus cannot provide optimal guidance for effective intervention. Based in part on a critique of our prior ''pathways'' model of big events, we suggest that cultural-historical activity theory (CHAT) may provide a useful framework for HIV research in this area. Using CHAT concepts, we also suggest a number of areas in which new measures should be developed to make such research possible.
Assessment of the long-term population-level effects of HIV interventions is an ongoing public he... more Assessment of the long-term population-level effects of HIV interventions is an ongoing public health challenge. Following the implementation of a Transmission Reduction Intervention Project (TRIP) in Odessa, Ukraine, in 2013-2016, we obtained HIV pol gene sequences and used phylogenetics to identify HIV transmission clusters. We further applied the birth-death skyline model to the sequences from Odessa (n = 275) and Kyiv (n = 92) in order to estimate changes in the epidemic's effective reproductive number (R e) and rate of becoming uninfectious (δ). We identified 12 transmission clusters in Odessa; phylogenetic clustering was correlated with younger age and higher average viral load at the time of sampling. Estimated R e were similar in Odessa and Kyiv before the initiation of TRIP; R e started to decline in 2013 and is now below R e = 1 in Odessa (R e = 0.4, 95%HPD 0.06-0.75), but not in Kyiv (R e = 2.3, 95%HPD 0.2-5.4). Similarly, estimates of δ increased in Odessa after the initiation of TRIP. Given that both cities shared the same HIV prevention programs in 2013-2019, apart from TRIP, the observed changes in transmission parameters are likely attributable to the TRIP intervention. We propose that molecular epidemiology analysis can be used as a post-intervention effectiveness assessment tool.
Background
Estimation of temporal changes in HIV transmission patterns can help to elucidate the ... more Background Estimation of temporal changes in HIV transmission patterns can help to elucidate the impact of preventative strategies and public health policies.
Methods Portuguese HIV-1 subtype B and G pol genetic sequences were appended to global reference datasets to identify country-specific transmission clades. Bayesian birth-death models were used to estimate subtype-specific effective reproductive numbers (Re). Discrete trait analysis (DTA) was used to quantify mixing among transmission groups.
Results We identified five subtype B Portuguese clades (n=26-79 sequences) and a large monophyletic subtype G Portuguese clade (n=236). We estimated that major shifts in HIV-1 transmission occurred around 1999 (95% Bayesian credible interval 1998-2000) and 2000 (1998-2001) for subtypes B and G, respectively. For subtype B, Re dropped from 1.91 (1.73-2.09) to 0.62 (0.52-0.72). For subtype G, Re decreased from 1.49 (1.39-1.59) to 0.72 (0.63-0.8). The DTA suggests that people who inject drugs (PWID) and heterosexuals were at the source of most (>80%) virus lineage transitions for subtypes G and B, respectively.
Conclusions The estimated declines in Re coincide with the introduction of highly active antiretroviral therapy and the scale-up of harm reduction for PWID. Inferred transmission events across transmission groups emphasize the importance of prevention efforts for bridging populations.
Background: While HIV-1 subtype B has caused a large epidemic in the western world, its transmiss... more Background: While HIV-1 subtype B has caused a large epidemic in the western world, its transmission in Ukraine remains poorly understood. We assessed the genetic diversity of HIV-1 subtype B viruses circulating in Ukraine, characterized transmission group structure, and estimated key evolutionary and epidemiological parameters. Methods: We analysed 120 HIV-1 subtype B pol sequences (including 46 newly generated) sampled from patients residing in 11 regions of Ukraine between 2002-2017. Phylogenies were estimated using maximum likelihood and Bayesian phylogenetic methods. A Bayesian molecular clock coalescent analysis was used to estimate effective population size dynamics and to date the most recent common ancestors of identified clades. A phylodynamic birth-death model was used to estimate the effective reproductive number (Re) of these clades. Results: We identified two phylogenetically distinct predominantly Ukrainian (≥75%) clades of HIV-1 subtype B. We found no significant transmission group structure for either clade, suggesting frequent mixing among transmission groups. The estimated dates of origin of both subtype B clades were around early 1970s, similar to the introduction of HIV-1 subtype A into Ukraine. Re for Clade 1 was estimated to be 1.42 (95% HPD 1.26-1.56) and 1.69 (95% HPD 1.49-1.84) for Clade 2. Discussion: The subtype B epidemic in the country is no longer concentrated in specific geographical regions or transmission groups. The study results highlight the necessity for strengthening preventive and monitoring efforts to reduce the further spread of HIV-1 subtype B.
Introduction
Providing HIV healthcare and Treatment as Prevention both depend on diagnosing HIV c... more Introduction Providing HIV healthcare and Treatment as Prevention both depend on diagnosing HIV cases, preferably soon after initial infection. We hypothesized that tracing risk networks recruits higher proportions of undiagnosed positives than outreach-based testing or respondent-driven sampling (RDS) in Odessa, Ukraine.
Methods The Transmission Reduction Intervention Project (TRIP) used risk network tracing to recruit sexual and injection networks of recently-infected and longer-term infected (LTs) seeds (2013 to 2016). Integrated Biobehavioural Surveillance (IBBS) (2013) used RDS to recruit people who inject drugs (PWID). Outreach Testing tested PWID for HIV at community outreach sites (2013 to 2016). Proportions of undiagnosed positives among those tested were compared TRIP versus IBBS; TRIP versus Outreach Testing and between TRIP arms. Costs were compared across the projects.
Results TRIP tested 1252 people (21% women) in seeds’ risk networks; IBBS tested 400 (18% women); Outreach Testing 13,936 (31% women). TRIP networks included a higher proportion of undiagnosed positives (14.6%) than IBBS (5.0%) or Outreach Testing (2.4%); odds ratio (OR) 3.25 (95% CI 2.07, 5.12) versus IBBS and 7.03 (CI 5.95, 8.31) versus Outreach Testing respectively. Findings remained significant in analyses stratified by sex and when PWID in TRIP networks were compared with Outreach Testing and IBBS. Within TRIP, recently-infected participants’ networks contained higher proportions of undiagnosed positives (16.3%) than LTs’ networks (12.2%); OR 1.41 (CI 1.01, 1.95). TRIP located undiagnosed positives less expensively than did RDS or Outreach Testing.
Conclusions TRIP's recruiting techniques, including prioritizing networks of the recently infected, find undiagnosed HIV-positive people efficiently. They should be integrated with standard practice to improve case-finding. Research should test these techniques in other socio-epidemiologic contexts.
Ukraine has one of the largest HIV epidemics in Europe, historically driven by people who inject ... more Ukraine has one of the largest HIV epidemics in Europe, historically driven by people who inject drugs (PWID). The epidemic showed signs of stabilization in 2012, but the recent war in eastern Ukraine may be reigniting virus spread. We investigated the movement of HIV-infected people within Ukraine before and during the conflict. We analyzed HIV-1 subtype-A pol nucleotide sequences sampled during 2012–2015 from 427 patients of 24 regional AIDS centers and used phylogeographic analysis to reconstruct virus movement among different locations in Ukraine. We then tested for correlations between reported PWID behaviors and reconstructed patterns of virus spread. Our analyses suggest that Donetsk and Lugansk, two cities not controlled by the Ukrainian government in eastern Ukraine, were significant exporters of the virus to the rest of the country. Additional analyses showed that viral dissemination within the country changed after 2013. Spearman correlation analysis showed that incoming virus flow was correlated with the number of HIV-infected internally displaced people. Additionally, there was a correlation between more intensive virus movement and locations with a higher proportion of PWID practicing risky sexual behaviors. Our findings suggest that effective prevention responses should involve internally displaced people and people who frequently travel to war-affected regions. Scale-up of harm reduction services for PWID will be an important factor in preventing new local HIV outbreaks in Ukraine.
Early treatment, soon after infection, reduces HIV transmissions and benefits patients. The Trans... more Early treatment, soon after infection, reduces HIV transmissions and benefits patients. The Transmission Reduction Intervention Project (TRIP) evaluated a network intervention to detect individuals recently infected (in the past 6 months). TRIP was conducted in Greece (2013–2015) and focused on drug injector networks. Based on HIV status, testing history, and the results of an assay to detect recent infections, TRIP classified drug injector “Seeds” into groups: Recent Seeds (RS), and Control Seeds with Long-term HIV infection (LCS). The network members of RS and LCS were traced for two steps. The analysis included 23 RS, 171 network members of the RS, 19 LCS, and 65 network members of the LCS. The per-seed number of recents detected in the network of RS was 5 times the number in the network of LCS (Ratio RS vs. LCS: 5.23; 95% Confidence Interval (CI): 1.54–27.61). The proportion of recents among HIV positives in the network of RS (27%) was approximately 3 times (Ratio RS vs. LCS: 3.30; 95% CI: 1.04–10.43) that in the network of LCS (8%). Strategic network tracing that starts with recently infected persons could support public health efforts to find and treat people early in their HIV infection.
Objective: Although our understanding of viral transmission among people who inject drugs (PWID) ... more Objective: Although our understanding of viral transmission among people who inject drugs (PWID) has improved, we still know little about when and how many times each injector transmits HIV throughout the duration of infection. We describe HIV dynamics in PWID to evaluate which preventive strategies can be efficient. Design: Due to the notably scarce interventions, HIV-1 spread explosively in Russia and Ukraine in 1990s. By studying this epidemic between 1995 and 2005, we characterized naturally occurring transmission dynamics of HIV among PWID. Method: We combined publicly available HIV pol and env sequences with prevalence estimates from Russia and Ukraine under an evolutionary epidemiology framework to characterize HIV transmissibility between PWID. We then constructed compartmental models to simulate HIV spread among PWID. Results: In the absence of interventions, each injector transmits on average to 10 others. Half of the transmissions take place within 1 month after primary infection, suggesting that the epidemic will expand even after blocking all the post–first month transmissions. Primary prevention can realistically target the first month of infection, and we show that it is very efficient to control the spread of HIV-1 in PWID. Treating acutely infected on top of primary prevention is notably effective. Conclusion: As a large proportion of transmissions among PWID occur within 1 month after infection, reducing and delaying transmissions through scale-up of harm reduction programmes should always form the backbone of HIV control strategies in PWID. Growing PWID populations in the developing world, where primary prevention is scarce, constitutes a public health time bomb.
Background We studied the association between sex in exchange for money, drugs or goods and HIV f... more Background We studied the association between sex in exchange for money, drugs or goods and HIV for women who inject drugs (WWID) in Ukraine, as previous data on this association from the post-USSR region are contradictory.
Methods Data come from the Integrated Bio-Behavioral Survey of Ukrainian people who inject drugs collected in 2011 using respondent-driven sampling. Participants were interviewed and tested with rapid HIV tests.
Results The sample included 2465 WWID (24% HIV positive); 214 (8.7%) of which reported having had exchange sex during the last 90 days. Crude analysis showed no association between exchange sex and HIV (OR = 0.644; 95% CI 0.385–1.077). No confounders were found to alter this result in a multivariable analysis. Further modeling showed that exchange sex modifies association between HIV and alcohol use: no association between HIV and daily alcohol use was found for those women who exchanged sex (OR = 1.699, 95% CI 0.737–3.956); while not engaging in sex work and daily using alcohol reduced odds to be HIV infected (OR = 0.586, 95% CI 0.389–0.885).
Conclusions Exchange sex may have less impact on the HIV status of WWID who are exposed to injecting risks. The finding that daily alcohol use appears protective against HIV among WWID who do not exchange sex requires more research.
The number of public health applications for molecular epidemiology and social
network analysis h... more The number of public health applications for molecular epidemiology and social network analysis has increased rapidly since the improvement in computational capacities and the development of new sequencing techniques. Currently, molecular epidemiology methods are used in a variety of settings: from infectious disease surveillance systems to the description of disease transmission pathways. The latter are of great epidemiological importance as they let us describe how a virus spreads in a community, make predictions for the further epidemic developments, and plan preventive interventions. Social network methods are used to understand how infections spread through communities and what the risk factors for this are, as well as in improved contact tracing and message-dissemination interventions. Research is needed on how to combine molecular and social network data as both include essential, but not fully sufficient information on infection transmission pathways. The main differences between the two data sources are that, firstly, social network data include uninfected individuals unlike the molecular data sampled only from infected network members. Thus, social network data include more detailed picture of a network and can improve inferences made from molecular data. Secondly, network data refer to the current state and interactions within the social network, while molecular data refer to the time points when transmissions happened, which might have happened years before the sampling date. As of today, there have been attempts to combine and compare the data obtained from the two sources. Even though there is no consensus on whether and how social and genetic data complement each other, this research might significantly improve our understanding of how viruses spread through communities.
Current ideas about HIV prevention include a
mixture of primarily biomedical interventions, socio... more Current ideas about HIV prevention include a mixture of primarily biomedical interventions, socio-mechanical interventions such as sterile syringe and condom distribution, and behavioral interventions. This article presents a framework for socially-integrated transdisciplinary HIV prevention that may improve current prevention efforts. It first describes one socially-integrated transdisciplinary intervention project, the Transmission Reduction Intervention Project. We focus on how social aspects of the intervention integrate its component parts across disciplines and processes at different levels of analysis. We then present socially-integrated perspectives about how to improve combination antiretroviral treatment (cART) processes at the population level in order to solve the problems of the treatment cascade and make ‘‘treatment as prevention’’ more effective. Finally, we discuss some remaining problems and issues in such a social transdisciplinary intervention in the hope that other researchers and public health agents will develop additional socially-integrated interventions for HIV and other diseases.
Background The emergence of HIV-1 in Russia came soon after the collapse of the Soviet Union. Wit... more Background The emergence of HIV-1 in Russia came soon after the collapse of the Soviet Union. With more than half a million cases within 5 years, the post-soviet Russian epidemic is one of the fastest and largest HIV outbreaks ever recorded. Although driven by intravenous drug users (IDUs), why the epidemic spread so rapidly and on a large scale is unclear. One popular practice between 1990 and 2000 was to use blood as a buff er or as a purifi er of homemade narcotics; this practice could account for the massive spread of HIV among Russian IDUs. We aimed to assess whether the epidemic was driven by contamination of narcotics at their source rather than by needle sharing.
Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmiss... more Past research suggests that as many as 50% of onward human immunodeficiency virus (HIV) transmissions occur during acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks. Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users’ community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent infection is identified, network members are interviewed about their risky behaviors, network information is collected, and blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes, educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care. Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected. Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT) sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other people with recent HIV infection and they can be successfully located without increasing stigma for project participants.
Economic and political instability and related ''big events'' are widespread throughout the globe... more Economic and political instability and related ''big events'' are widespread throughout the globe. Although they sometimes lead to epidemic HIV outbreaks, sometimes they do not-and we do not understand why. Current behavioural theories do not adequately address these processes, and thus cannot provide optimal guidance for effective intervention. Based in part on a critique of our prior ''pathways'' model of big events, we suggest that cultural-historical activity theory (CHAT) may provide a useful framework for HIV research in this area. Using CHAT concepts, we also suggest a number of areas in which new measures should be developed to make such research possible.
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Papers by Tetyana Vasylyeva
Estimation of temporal changes in HIV transmission patterns can help to elucidate the impact of preventative strategies and public health policies.
Methods
Portuguese HIV-1 subtype B and G pol genetic sequences were appended to global reference datasets to identify country-specific transmission clades. Bayesian birth-death models were used to estimate subtype-specific effective reproductive numbers (Re). Discrete trait analysis (DTA) was used to quantify mixing among transmission groups.
Results
We identified five subtype B Portuguese clades (n=26-79 sequences) and a large monophyletic subtype G Portuguese clade (n=236). We estimated that major shifts in HIV-1 transmission occurred around 1999 (95% Bayesian credible interval 1998-2000) and 2000 (1998-2001) for subtypes B and G, respectively. For subtype B, Re dropped from 1.91 (1.73-2.09) to 0.62 (0.52-0.72). For subtype G, Re decreased from 1.49 (1.39-1.59) to 0.72 (0.63-0.8). The DTA suggests that people who inject drugs (PWID) and heterosexuals were at the source of most (>80%) virus lineage transitions for subtypes G and B, respectively.
Conclusions
The estimated declines in Re coincide with the introduction of highly active antiretroviral therapy and the scale-up of harm reduction for PWID. Inferred transmission events across transmission groups emphasize the importance of prevention efforts for bridging populations.
Methods: We analysed 120 HIV-1 subtype B pol sequences (including 46 newly generated) sampled from patients residing in 11 regions of Ukraine between 2002-2017. Phylogenies were estimated using maximum likelihood and Bayesian phylogenetic methods. A Bayesian molecular clock coalescent analysis was used to estimate effective population size dynamics and to date the most recent common ancestors of identified clades. A phylodynamic birth-death model was used to estimate the effective reproductive number (Re) of these clades.
Results: We identified two phylogenetically distinct predominantly Ukrainian (≥75%) clades of HIV-1 subtype B. We found no significant transmission group structure for either clade, suggesting frequent mixing among transmission groups. The estimated dates of origin of both subtype B clades were around early 1970s, similar to the introduction of HIV-1 subtype A into Ukraine. Re for Clade 1 was estimated to be 1.42 (95% HPD 1.26-1.56) and 1.69 (95% HPD 1.49-1.84) for Clade 2.
Discussion: The subtype B epidemic in the country is no longer concentrated in specific geographical regions or transmission groups. The study results highlight the necessity for strengthening preventive and monitoring efforts to reduce the further spread of HIV-1 subtype B.
Providing HIV healthcare and Treatment as Prevention both depend on diagnosing HIV cases, preferably soon after initial infection. We hypothesized that tracing risk networks recruits higher proportions of undiagnosed positives than outreach-based testing or respondent-driven sampling (RDS) in Odessa, Ukraine.
Methods
The Transmission Reduction Intervention Project (TRIP) used risk network tracing to recruit sexual and injection networks of recently-infected and longer-term infected (LTs) seeds (2013 to 2016). Integrated Biobehavioural Surveillance (IBBS) (2013) used RDS to recruit people who inject drugs (PWID). Outreach Testing tested PWID for HIV at community outreach sites (2013 to 2016). Proportions of undiagnosed positives among those tested were compared TRIP versus IBBS; TRIP versus Outreach Testing and between TRIP arms. Costs were compared across the projects.
Results
TRIP tested 1252 people (21% women) in seeds’ risk networks; IBBS tested 400 (18% women); Outreach Testing 13,936 (31% women). TRIP networks included a higher proportion of undiagnosed positives (14.6%) than IBBS (5.0%) or Outreach Testing (2.4%); odds ratio (OR) 3.25 (95% CI 2.07, 5.12) versus IBBS and 7.03 (CI 5.95, 8.31) versus Outreach Testing respectively. Findings remained significant in analyses stratified by sex and when PWID in TRIP networks were compared with Outreach Testing and IBBS. Within TRIP, recently-infected participants’ networks contained higher proportions of undiagnosed positives (16.3%) than LTs’ networks (12.2%); OR 1.41 (CI 1.01, 1.95). TRIP located undiagnosed positives less expensively than did RDS or Outreach Testing.
Conclusions
TRIP's recruiting techniques, including prioritizing networks of the recently infected, find undiagnosed HIV-positive people efficiently. They should be integrated with standard practice to improve case-finding. Research should test these techniques in other socio-epidemiologic contexts.
Methods Data come from the Integrated Bio-Behavioral Survey of Ukrainian people who inject drugs collected in 2011 using respondent-driven sampling. Participants were interviewed and tested with rapid HIV tests.
Results The sample included 2465 WWID (24% HIV positive); 214 (8.7%) of which reported having had exchange sex during the last 90 days. Crude analysis showed no association between exchange sex and HIV (OR = 0.644; 95% CI 0.385–1.077). No confounders were found to alter this result in a multivariable analysis. Further modeling showed that exchange sex modifies association between HIV and alcohol use: no association between HIV and daily alcohol use was found for those women who exchanged sex (OR = 1.699, 95% CI 0.737–3.956); while not engaging in sex work and daily using alcohol reduced odds to be HIV infected (OR = 0.586, 95% CI 0.389–0.885).
Conclusions Exchange sex may have less impact on the HIV status of WWID who are exposed to injecting risks. The finding that daily alcohol use appears protective against HIV among WWID who do not exchange sex requires more research.
network analysis has increased rapidly since the improvement in computational
capacities and the development of new sequencing techniques. Currently, molecular
epidemiology methods are used in a variety of settings: from infectious disease
surveillance systems to the description of disease transmission pathways. The latter
are of great epidemiological importance as they let us describe how a virus spreads in
a community, make predictions for the further epidemic developments, and plan
preventive interventions. Social network methods are used to understand how
infections spread through communities and what the risk factors for this are, as well
as in improved contact tracing and message-dissemination interventions. Research is
needed on how to combine molecular and social network data as both include
essential, but not fully sufficient information on infection transmission pathways. The
main differences between the two data sources are that, firstly, social network data
include uninfected individuals unlike the molecular data sampled only from infected
network members. Thus, social network data include more detailed picture of a
network and can improve inferences made from molecular data. Secondly, network
data refer to the current state and interactions within the social network, while
molecular data refer to the time points when transmissions happened, which might
have happened years before the sampling date. As of today, there have been attempts
to combine and compare the data obtained from the two sources. Even though there is
no consensus on whether and how social and genetic data complement each other, this
research might significantly improve our understanding of how viruses spread through
communities.
mixture of primarily biomedical interventions, socio-mechanical
interventions such as sterile syringe and condom
distribution, and behavioral interventions. This article
presents a framework for socially-integrated transdisciplinary
HIV prevention that may improve current prevention
efforts. It first describes one socially-integrated
transdisciplinary intervention project, the Transmission
Reduction Intervention Project. We focus on how social
aspects of the intervention integrate its component parts
across disciplines and processes at different levels of analysis.
We then present socially-integrated perspectives
about how to improve combination antiretroviral treatment
(cART) processes at the population level in order to solve
the problems of the treatment cascade and make ‘‘treatment
as prevention’’ more effective. Finally, we discuss some
remaining problems and issues in such a social transdisciplinary
intervention in the hope that other researchers and
public health agents will develop additional socially-integrated
interventions for HIV and other diseases.
acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage
of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project
Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks.
Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users’
community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent
infection is identified, network members are interviewed about their risky behaviors, network information is collected, and
blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes,
educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care.
Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected.
Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent
infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT)
sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network
members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently
infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results
provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other
people with recent HIV infection and they can be successfully located without increasing stigma for project participants.
Estimation of temporal changes in HIV transmission patterns can help to elucidate the impact of preventative strategies and public health policies.
Methods
Portuguese HIV-1 subtype B and G pol genetic sequences were appended to global reference datasets to identify country-specific transmission clades. Bayesian birth-death models were used to estimate subtype-specific effective reproductive numbers (Re). Discrete trait analysis (DTA) was used to quantify mixing among transmission groups.
Results
We identified five subtype B Portuguese clades (n=26-79 sequences) and a large monophyletic subtype G Portuguese clade (n=236). We estimated that major shifts in HIV-1 transmission occurred around 1999 (95% Bayesian credible interval 1998-2000) and 2000 (1998-2001) for subtypes B and G, respectively. For subtype B, Re dropped from 1.91 (1.73-2.09) to 0.62 (0.52-0.72). For subtype G, Re decreased from 1.49 (1.39-1.59) to 0.72 (0.63-0.8). The DTA suggests that people who inject drugs (PWID) and heterosexuals were at the source of most (>80%) virus lineage transitions for subtypes G and B, respectively.
Conclusions
The estimated declines in Re coincide with the introduction of highly active antiretroviral therapy and the scale-up of harm reduction for PWID. Inferred transmission events across transmission groups emphasize the importance of prevention efforts for bridging populations.
Methods: We analysed 120 HIV-1 subtype B pol sequences (including 46 newly generated) sampled from patients residing in 11 regions of Ukraine between 2002-2017. Phylogenies were estimated using maximum likelihood and Bayesian phylogenetic methods. A Bayesian molecular clock coalescent analysis was used to estimate effective population size dynamics and to date the most recent common ancestors of identified clades. A phylodynamic birth-death model was used to estimate the effective reproductive number (Re) of these clades.
Results: We identified two phylogenetically distinct predominantly Ukrainian (≥75%) clades of HIV-1 subtype B. We found no significant transmission group structure for either clade, suggesting frequent mixing among transmission groups. The estimated dates of origin of both subtype B clades were around early 1970s, similar to the introduction of HIV-1 subtype A into Ukraine. Re for Clade 1 was estimated to be 1.42 (95% HPD 1.26-1.56) and 1.69 (95% HPD 1.49-1.84) for Clade 2.
Discussion: The subtype B epidemic in the country is no longer concentrated in specific geographical regions or transmission groups. The study results highlight the necessity for strengthening preventive and monitoring efforts to reduce the further spread of HIV-1 subtype B.
Providing HIV healthcare and Treatment as Prevention both depend on diagnosing HIV cases, preferably soon after initial infection. We hypothesized that tracing risk networks recruits higher proportions of undiagnosed positives than outreach-based testing or respondent-driven sampling (RDS) in Odessa, Ukraine.
Methods
The Transmission Reduction Intervention Project (TRIP) used risk network tracing to recruit sexual and injection networks of recently-infected and longer-term infected (LTs) seeds (2013 to 2016). Integrated Biobehavioural Surveillance (IBBS) (2013) used RDS to recruit people who inject drugs (PWID). Outreach Testing tested PWID for HIV at community outreach sites (2013 to 2016). Proportions of undiagnosed positives among those tested were compared TRIP versus IBBS; TRIP versus Outreach Testing and between TRIP arms. Costs were compared across the projects.
Results
TRIP tested 1252 people (21% women) in seeds’ risk networks; IBBS tested 400 (18% women); Outreach Testing 13,936 (31% women). TRIP networks included a higher proportion of undiagnosed positives (14.6%) than IBBS (5.0%) or Outreach Testing (2.4%); odds ratio (OR) 3.25 (95% CI 2.07, 5.12) versus IBBS and 7.03 (CI 5.95, 8.31) versus Outreach Testing respectively. Findings remained significant in analyses stratified by sex and when PWID in TRIP networks were compared with Outreach Testing and IBBS. Within TRIP, recently-infected participants’ networks contained higher proportions of undiagnosed positives (16.3%) than LTs’ networks (12.2%); OR 1.41 (CI 1.01, 1.95). TRIP located undiagnosed positives less expensively than did RDS or Outreach Testing.
Conclusions
TRIP's recruiting techniques, including prioritizing networks of the recently infected, find undiagnosed HIV-positive people efficiently. They should be integrated with standard practice to improve case-finding. Research should test these techniques in other socio-epidemiologic contexts.
Methods Data come from the Integrated Bio-Behavioral Survey of Ukrainian people who inject drugs collected in 2011 using respondent-driven sampling. Participants were interviewed and tested with rapid HIV tests.
Results The sample included 2465 WWID (24% HIV positive); 214 (8.7%) of which reported having had exchange sex during the last 90 days. Crude analysis showed no association between exchange sex and HIV (OR = 0.644; 95% CI 0.385–1.077). No confounders were found to alter this result in a multivariable analysis. Further modeling showed that exchange sex modifies association between HIV and alcohol use: no association between HIV and daily alcohol use was found for those women who exchanged sex (OR = 1.699, 95% CI 0.737–3.956); while not engaging in sex work and daily using alcohol reduced odds to be HIV infected (OR = 0.586, 95% CI 0.389–0.885).
Conclusions Exchange sex may have less impact on the HIV status of WWID who are exposed to injecting risks. The finding that daily alcohol use appears protective against HIV among WWID who do not exchange sex requires more research.
network analysis has increased rapidly since the improvement in computational
capacities and the development of new sequencing techniques. Currently, molecular
epidemiology methods are used in a variety of settings: from infectious disease
surveillance systems to the description of disease transmission pathways. The latter
are of great epidemiological importance as they let us describe how a virus spreads in
a community, make predictions for the further epidemic developments, and plan
preventive interventions. Social network methods are used to understand how
infections spread through communities and what the risk factors for this are, as well
as in improved contact tracing and message-dissemination interventions. Research is
needed on how to combine molecular and social network data as both include
essential, but not fully sufficient information on infection transmission pathways. The
main differences between the two data sources are that, firstly, social network data
include uninfected individuals unlike the molecular data sampled only from infected
network members. Thus, social network data include more detailed picture of a
network and can improve inferences made from molecular data. Secondly, network
data refer to the current state and interactions within the social network, while
molecular data refer to the time points when transmissions happened, which might
have happened years before the sampling date. As of today, there have been attempts
to combine and compare the data obtained from the two sources. Even though there is
no consensus on whether and how social and genetic data complement each other, this
research might significantly improve our understanding of how viruses spread through
communities.
mixture of primarily biomedical interventions, socio-mechanical
interventions such as sterile syringe and condom
distribution, and behavioral interventions. This article
presents a framework for socially-integrated transdisciplinary
HIV prevention that may improve current prevention
efforts. It first describes one socially-integrated
transdisciplinary intervention project, the Transmission
Reduction Intervention Project. We focus on how social
aspects of the intervention integrate its component parts
across disciplines and processes at different levels of analysis.
We then present socially-integrated perspectives
about how to improve combination antiretroviral treatment
(cART) processes at the population level in order to solve
the problems of the treatment cascade and make ‘‘treatment
as prevention’’ more effective. Finally, we discuss some
remaining problems and issues in such a social transdisciplinary
intervention in the hope that other researchers and
public health agents will develop additional socially-integrated
interventions for HIV and other diseases.
acute and recent HIV infection. It is clearly important to develop interventions which focus on this highly infectious stage
of HIV infection to prevent further transmission in the risk networks of acutely and recently infected individuals. Project
Protect tries to find recently and acutely infected individuals and prevents HIV transmission in their risk networks.
Participants are recruited by community health outreach workers at community-based HIV testing sites and drug users’
community venues, by coupon referrals and through referrals from AIDS clinics. When a network with acute/recent
infection is identified, network members are interviewed about their risky behaviors, network information is collected, and
blood is drawn for HIV testing. Participants are also educated and given prevention materials (condoms, syringes,
educational materials); HIV-infected participants are referred to AIDS clinics and are assisted with access to care.
Community alerts about elevated risk of HIV transmission are distributed within the risk networks of recently infected.
Overall, 342 people were recruited to the project and screened for acute/recent HIV infection. Only six index cases of recent
infection (2.3% of all people screened) were found through primary screening at voluntary counseling and testing (VCT)
sites, but six cases of recent infection were found through contact tracing of these recently infected participants (7% of network
members who came to the interview). Combining screening at VCT sites and contact tracing the number of recently
infected people we located as compared to VCT screening alone. No adverse events were encountered. These first results
provide evidence for the theory behind the intervention, i.e., in the risk networks of recently infected people there are other
people with recent HIV infection and they can be successfully located without increasing stigma for project participants.